This
enzyme
has
been
found
to
exist
in
all
cells
and
links
together
ribonucleotides
by
catalysing
the
formation
of
the
internucleotide
3'-5'
phosphodiester
bonds
that
hold
the
RNA
backbone
together
.
This
enzyme
functions
only
in
the
presence
of
DNA
and
the
RNA
thus
synthesized
has
a
complementary
sequence
to
that
of
the
DNA
template.
DNA
dependant
RNA
polymerase
is
a
multisubunit
complex.
The
active
form
consists
of
five
different
polypeptides,
namely β,β’,α2,ω and δ with
molecular
weights
of
150,000;
160,000;
90,000;
40,000;
10,000
respectively
Each
peptides
except α,
appears
only
once
giving
the
complete
holoenzyme β,β’,α2,ω and δ)
with
a
molecular
weight
around
0.5
X
106
daltons.
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